Cryogenic storage tank



July 27, 1965 E. L. sMn'H ETAL cRYoGENIC 'sToRAGE TANK Original FiledDec. 24, 1962 J V 1 ww f a Q w M ,fm m 5. W f a JMF A e W f I I I I I II I I I. 17./ Z l l l l I I I I I I I I MM .I I I I ,I I. I I l I I I iI I I I lllllllllllllllllllllllllllll' July 27, 1965 E. L. sMl'rH ETAL3,196622 CRYOGENIC STORAGE TANK original Filed Dec. 24, 1982 5sneets-sheet 2 Aff//ur f. u/fy INVENTORJ July 27, 1965 E. L. sMn'H ETAL3,1%.622

CRYOGENIC STORAGE TANK Original Filed Dec. 24, 1962 5 Sheets-Sheet 3 Arur fi. Duffy INVENToRs /UTOR/VEVJ July 27, 1965 E.L.sM|1'H ETAL3,196,622

'CRfx'OGENIC STORAGE TANK Original Filed Dec. 24, 1962 5 Sheets-Sheet 5United States Patent O This invention relates to storage tanks, andparticui larly to cryogenic storage tanks for storing such materials asliquefied natural gas and is a continuation of application No. 246,816,filed December 24, 1962, now abandoned. The particular designs of tanksembodying this invention illustrated in the drawings were made for thestorage of liquefied natural gas and, while the tanks might be used forstoring other cryogenic iluids, the description will be directed to atank specifically designed for the storage of liquefied natural gas.

Recent years have seen the ever increasing transmission of natural gasfrom remote .gas fields to areas of dense population. This gas is beingused in commercial establishments as well as in homes for power andheating. As the gas is transported over tremendous distances, the amountof gas available for a given period of time is determined by the size ofthe pipeline and the pressure at which it is operated.

During peak demand conditions, such as occur on very cold days, thecustomer demand for gas is much greater than normal. Means have beensought to provide this peak demand without the construction of pipelinescapable of supplying this demand on a year-round basis, because the costof such lines would be uneconomical. For instance, in some areas of thecountry underground storage of gas near the point of ultimate uselhasprovided a solution. In these instances natural gas is injected intounderground earth formations in the gaseous phase during the summermonths to provide a ready source of gas for peak demand during theWinter.

Another' solution to this problem is the storage of natural gas intanks. Oflcourse, to be practical the gas must be liquefied andmaintained in storage in liquid form at about -258 F., as the tremendousvolumes necessary for peak demand would make the cost of storage ingaseous form prohibitive.

It is an object of this invention to provide a practical tankconstruction capable of being positioned all or partially below groundlevel, which tank is within the realm of economic storage of liquefiednatural gas.

For economical reasons a tank for storing liquefied natural gas forpe'ak demand purposes 'must be o-f considerable size. For instance, itmay have a diameter in excess of 'one hundred feet, and a height inex-cess of fifty feet. To place the tank underground requires, as apractical matter, that the insulation be carried within the tank. Due tovapors which are constantly formed within the tank, a liner serving as aliquid and vapor barrier must also be provided. These provisions forinsulation and liner must be compatible with the very large dimensionalchanges of the tank due to a change in temperature in the tank fromambient conditions when empty down to a temperature lower than -250 F.It will be appreciated that each hole Vwhich is made throughthe linerand insulation material is a potential source of leak, and everystructural member `which eXtends through the insulation and liner is apotential source of heat loss. For these reasons, it is preferred toprovide a means of maintaining the insulation and liner within the tankwhich requires as few direct supports from the shell of the tank aspossible.

3,1%,622 Patentecl July 27, 1965 ice It is accordingly an object of thisinvention to provide a cryogenic tank with insulation material and aliner which are capable of functioning in the temperatures expected, andin which a minimum number of direct supports from the shell of the tankare required.

A more specific object is to provide a cryogenic tank with means forsupporting a lining of insulation material and a lining of imperviousmaterial to act as a liquid and vapor barrier in which there are nodirect supports from the side wall or floor of the tank which requirethat holes be made in either the insulation material or the liner.

Notwithstanding every etfort to prevent leaks from the tank, some mayoccur, and these should be detected as quickly as possible to minimizefire hazard.

Another vobject =of this invention is to provide a system for detectingany leak which may occur in the underground cryogenic vessel, and toprovide for removal of small amounts of vapors which might penetrate theliner before they reach the exterior of the tank.

In time, the earth `surrou'ndng the wall of the tank and the earthbeneath the tank Will become very cold. During excavation a substantial4area around the tank will be removed, and in back-filling a material maybe chosen in which frost heave is not a problem. It may, however, benecessary to support the tank on or adjacent to earth which will presenta frost heave problem, and it is desirable to provide a means forpreventing damage to the tank due to frost heave.

Another object is to control the temperature of the earth surroundingthe buried tank in which frost heave might occur at a temperature abovefreezing to prevent frost heave without undue heat input to the tank.

Other objects, features and advantages of the invention Will be apparentfrom the drawings, the specification and the claims. i

In the drawings, wherein like reference numerals indicate like parts andwherein illustrative embodiments of the invention are shown:

FIGURE 1 is a cross-sectional view through a tank embodying thisinvention;

FIGURES 2A and 2B are cross-sectional views on an enlarged scale of theupper and lower corners of the tank of FIGURE 1, with FIGURE 2B being acontinuation of FIGURE 2A but with a substantial portion of theintermediate section of the tank between the top and bottom omitted;

FIGURE 3 is a horizontal cross-section through the side wall of the tanktaken along the line 3-3 of FIG- URE 2B; i

FIGURE 4 is an elevational view of a fragment of the side wall of thetank taken from the inside of the tank;

FIGURE 5 is a view in Vertical cross-section through a modifiedform ofthis invention;

FIGURE 6 is a view along the line 6-6 of FIGURE 5 on an enlarged scale;and

FIGURE 7 is a view in cross-section of the lower corner of a` furthermodified form of tank,

Referring first to FIGURES l through 4, there is shown the preferredform of this invention embodied in an underground cryogenic tank. Itwill be appreciated that theprinciples of this invention are alsoapplicable to 'an above-ground tank, but their greatest value lies intheir use in a sub-surface tank.

As shown in FIGURE 1, the location for the tank is first excavated asrepresented by the surface 10, and a backfill of a selected material 11spread `over the bottom of the excavation to prevent frost heave. Beforebackfilling, suitable coils as shown at 12 may be placed in the backfillto control temperature in a frost heave susceptible soil, as will bedescribed hereinafter.

The tank, which is built in the excavation and on the backfill 11, hasan outer supporting shell of concrete.

This supporting shell includes the fioor 13, the side wall 14 and thetop or roof 15. As shown, the preferred side wall configuration iscylindrical.

The contraction and expansion of the fioor 13 and wall 14- withdiffering temperature conditions will not be alike', and the temperatureof the wall 14 will not only vary progressively along the wallvertically, but will be different in magnitude from the temperature ofthe fioor. Forthis reason, a vessel of the type shown in FlGURE 1 shouldhavethe side wall 14 separated from the fioor 13, and provision shouldbe made to perrnitthe side wall to slide over the base vor fioor.

Referring to FIGURE 2B, there is shown a preferredV form of sliding walland base. After the fioor 13 has been poured and allowed to cool, theplate 16, is set in concrete ma on top of the fioor. Suitvable ties 17are preferably embedded in the fioor 13, and nuts 13 on these ties areused to assist in tying the plate 16 in place. A suitable angle` irony19 may be providedat spaced intervals, or continuously if desired,about the outer periphery of plate to act as a stop orretainer.

A suitable jsliding means 21 rest's upon the plate 15. This means 21 maybe aV thin layer of any suitable material which will perrnit relativeslidingimovement between the wall 14 andthe fioor 13. Preferably, Teflonis employed for thisv purpose. In order to protect the joint againstforeignl materials during construction, a Sheet metal Shield 22 may beformed over ,the joint in the manner shown in FIGURE 2B tovexcludelforeign material from the V`area of the Tefion sheet.

After the slid'ing joint is completed, the sidel wall 14 maybeconstructed by a cast-in-place methodpor erected from precastsections. pi

Preferably, the side wall 14 is pre-stressed with. a wrapping of vWire23 in 'a continuous hor-izontally extending loop to. provide additionalstrength for the side wall. Also, it might be noted that a backfillladjacent the side wall 14 may also serve to supply a portion, of thepoststress to the wall 14 and the design ofI the wall' mayadvantageously take into account the post-stressing value of thebackfill indicated generally at 24. v The tank is completed by .thetopr15 which lis preferably an arched concrete dome. Other types of roofobviously might be utilied and the roof might be fabricated fromothermaterials, but an arched dome is preferred.V

Insulation means indicated generally at 25 completely lines the tank..The insulation means 25 is provided by a plurality of 'blocks ofinsulating material, such as solid block 26.* Preferably as shown aplurality of layers of insulating jmaterial such as shown atv 27, 28 and29 is provided. The several blocks of insulation material are shiplappedas 'shown at 31, for instan'ce, `and the joints in adjacent` layers ofinsulation are staggered, as will be readily apparent from aconsideration of FIGURES 2, 3 and 4. This construction will giveSuperior results in reducing heat loss across, the insulation. i

Preferably, one of the cellular expanded plastics provides theinsulation material. For instance, the insulation material might beconstructed from urethane,

-Sty1ofoam,'or other cellular expanded plastics or other typesofmaterial having similar Vinsulation and strength properties at lowtemperatures. Investigation has pnoved urethane to be a Superiormaterial. While the insulation material is not relied upon to provide aliquid and vapor barrier, it must be recognized that failure of thevapor barrier is possible, and an insulating material which would retardloss of the stored 'fluid would be preferred.

to as a liner, completely lines the tank and provides a liquid and vaporbarrier.

The liner may be provided from any suitable material which lisimpervious to and chemically compatible with the liquid 'being stored,andwhich has suitable mechanical properties vat very low temperatures.Obviously, it must be a material which is non-brittle, as it must becontinuous and preferably 'it should be susceptible of being easilyfabricated in place. For instance, it is preferred that the insulationmaterial =be factory prefabricated in as large Sections as can behandled, and that final fabrication take place within the tank. Asuitable liner may be provided by a polyester film obtainable from theE.I. du Pont de Nemours Company, known as Mylar. It is preferred thatthis film `be laminated to each side of an aluminum foil. To thisassernbly a fabric is also preferably -laminated to provide tearresistance.

It is very important that this liner have as few holes as possibletherethroug'h. It is -also preferred to have as few paths of heattransmission as possiblel through the insulation material. For thesereasons, it is preferred to maintain the fioor and side wall insulationmaterial and liner in place by a system totally within the interior ofthe tank, i.e., a system which 'is not attached to either the fioor orthe side walls. By erecting suitable columns within the vessel, theliner and insulation material lining the roof of the tank could also beso supported. In the illustrated embodiment, however, this is notnecessary due to the provision of the space 33 between the insulatronand root which additionally assists in insulating the top of the tank.

'The liner is preferably sandwi-ched between the innermost layer 29 andthe intermediate layer 28 of insulation material providing protectionfor theliner. It has been found that urethane has sufiicient strength topermit a limited amount of construction activity over the urethane ifadequate precautions are taken against imposing too great a force on theurethane.

In laying the insulation material and liner, the sandwich of liner andinsulation .material is first laid on the fioor in the mannerillustrated in FIGURE 2B. As the material is laid, a layer of plywood 34is put down over the insulation-liner to protect it. After theinsulationliner Sandwich has been laid on the floor and completelycovered with plywood, a slab-'of concrete 35 is preferably cast in placeover plywood 34. This slabserves to hold the insulation-liner Sandwichin. place, and particularly to prevent, the inner layer 29 of theinsulating material from fioating on the body of liquid. Also, the slab35 serves as a protection for the insulating material-liner Sandwichduring construction of the remainder of the insulation.

The means for holding the Sandwich of insulation material-liner in placeagainst the side wall is provided by a grid work of structural membersindicated at 3d and best shown'in FIGURE 4. This grid work includes aplurality of shoes 37 which engage the innermost layer of insulationmaterial and hold it in place. The shoes 37 are held in spaced VerticalVrelationship in the tank by a plurality of risers 38 which extendvertically along the side walls of the tank.

In order to firmly hold the Sandwich of insulation and liner' materialsagainst the shell of the tank, means is provided for urging theshoes'radially outwardly. Such means may be provided by a plurality ofcircumferentially spaced Springs 39 between adjacent shoes 37 to urgeadjacent shoes away from each other and give a resultant i outwardcomponent of force. As best shown in 'FIG- URES 3 and 4, the shoes 37are provided with abutments 41 at their ends between whichthe Springs 39are compressed. A suitable bolt 42 extends through the abutments 41 andthe spring 39 to insure that the spring remains in place. As eachsectionof the wall is put in place, the nuts 43 on bolts 42 may be runup to compress the Springs topthe extent shownnin FIGURE 4.`V Then,after the shoes are all in place so that each shoe forms a part of acomplete circle of shoes, the nuts 43 may be backed off so that thesprings 39 will be effective to urge the shoes away from each other, andthus hold the insulation material-liner Sandwich firmly in place. Itwill be appreciated that with the construction outlined above, there isno need for any bolts, keys, or the like, extending radially inwardlyfrom the side wall 14 on which the insulation material-liner might behung. This avoids holes through the insulation material and the linerand permits these elements to function at maximum efficiency. It mightbe noted that it is, of course, possible for the stored liquid to findits way to the liner, at least adjacent the joints between adjacentblocks which make up the inner layer of insulation material. It isbelieved, however, that this inner layer of insulation material willstill function and will be beneficial as compared to the use of a moreprotective layer for the vapor barrier 32. In any event, the inner layerfunctions as insulation material above the liquid level aiid, as thislevel will change from time to time, the inner protective layer ispreferably of a good insulation material. Obviously material having poorinsulation properties might be used as an inner layer to provide aprotective layer for the liner.

It is also pointed out that the cellular plastic Sandwich with aninterior liner provides a support for the liner which will give and nottear the liner. Thus, if the insulation materal of the floor is notexactly smooth, the insulation material will give and not tear the lineras would be the case with a stiff protective material against the liner.

By reference to FIGURE 2A, the preferred form of lining the top of thetank will be observed. In this instance a thin sheet of aluminum 44suitably reinforced by structural components or members 45 is suspendedfrom the roof by Suspension rods 46; These rods support the aluminumSheet 44 by means of a suitable washer 47 of larger size than the holethrough the aluminurn sheet and a suitable nut 48 thereon. If desired,the vapor barrier 44 may be sealed to the hanger but this is notnecessary as any vapors which may escape into the static vapor space 33may be recovei'ed along with the vapors below the top insulation forventing or reliquefaction. It will be appreciated that during storagethe cold liquid is subject to vapor boil-ofl, and these vapors areremoved from the tank and either vented, flai'ed, or reliquefied, andre-introduced to the tank. Thus, any vapors which escape into the deadspace 33 may be treated in the same manner as vapors in the tank, ifdesired.

To provide for removal of relatively small `amounts of .vapor due topermeation through the liner, there is provided about the entire tank aseries of purge spaces. In the floor of the tank and cast into theconcrete 13 are a plurality of conduits or grooves 49 which extendacross the entire floor. Preferably, these spaces extend radiallyoutward from the center of the iioor and each conduit 49 communicateswith a like purge space or conduit 51 extending vertically up the insideof the concrete wall 14. These purge spaces 51 are also narrow groovescast in the side wall and each extends upwardly and communicates with apipe such as shown at 52.

.Suitable-connection is made between the purge spaces 49 in the fioorand the purge spaces 51. in 'the side wall in any desired manner such asthrough a small pipe 53 extending through the insulation material from apurge space 49 to a purge space 51. The dead space 33 m the roof may bepurged by introducing purge gas through `inlet conduits 54 andwithdrawing gas through the Outlet conduit 55. With this construction itwill be apparent that by sweeping the purge system with a suitable gasany vapors which may have permeated through the vapor barrier may becollected and reliquefied.

As previously mentioned, frost heave can be Controlled by selectingbackfill material. However, if backfill is not 6 sufficent to controlfrost heave in the virgin soil adjacent to the selected backfill, thisproblem may be overcome by burying conduits 12 beneath the floor of thevessel. While a single continuous conduit 12 is indicated, it will beunderstood that this single conduit could be provided by a number ofbundles of conduit.

During filling of the tank, gas froin the source pipeline may be passedthrough conduit 12 and thence to the liquefaction equipment indicatedschematically at 56. The liquefied natural gas is injected into the tankfrom liquefaction equipment 56 through the conduit 57. It will beappreciated that heat exchange will occur in the coil 12 between thecold surrounding earth and the relatively warmer gas. In this Way thetemperature immediately below the tank may be kept above freezing toprevent frost heavel During the time that the tank is not being .filled,natural gas from the source ppeline may be passed `through conduit 12and thence returned to the pipeline through the line 58. If it is notdesired to pass gas through coil 12 when the tank is not being filled,then other heating means may be provided beneath the tank formaintaining the temperature above the freezing point. i

During peak needs, the liquefied natural gas may be removed from thetank by the pump indicated generally at 59.

Reference is now made to FIGURE 5` which is identical with the tankpreviously explained except that a different means of supporting theinsulation-vapor barrier against the side wall is shown. This means hasthe ad- Vantage of counterbalancing or absorbing some of the stresses inthe roof 15.

In the FIGURE 5 form of the invention a plurality of verticallyextending structural members 61 are spaced circumferentially about thetank adjacent the side wall 14. These structural members are suitablyanchored at their base against movement away from the side wall.Conveniently they may have a member 62 which engages the periphery ofthe concrete slab 35 to hold each structural member against radialinward movement.

Each structural member 61 has its upper end tied to the roof 15 by asuitable tie member 63. As shown, the member 63 is cast in the roof andsupports the structural member 61 in the Vertical position and will, ofcourse, resist radial inward movement of the structural member.

A plurality of shoes 64 extend circumferentially about the interior ofthe tank and bear against the insulationvapor barrier 25, SuitableSprings 65 are held in compressionbetween the several shoes 64 and theseveral structural members 61 to thus urge the shoes away from thestructural members and hold the insulation-vapor barrier firmly in placeagainst the side wall.

It will be appreciated from the above explanation that the force exertedby the several Springs 65 is effective as an inwardly directed force onthe tie means 63 at the top of the structural member. As this force istransmitted to the roof 15, and preferably at the outer periphery of theroof 15, there results a radially inward pull on the roof 15. As theroof 15 is an arched dome, there are present in the roof stressesresulting in a radially outward force being present in the outerperiphery of the roof. This radiallyV outward force in the roof due tothe dome construction is offset or counterbalanced in part by the forceon the ties 63 to thus reduce the stresses in the roof to a point nearerequilibrium. i

In FIGURE 7 there is shown an alternative embodiment of the tank ofFIGURE 1. This embodiment of the tank will be identical with that ofFIGURE 1 except that the side wall 68 will be cast integrally with thefloor and footer. The footer 67 is annular and underlies the side wall68 about the entire periphery of the tank. As noted hereinabove, verylarge expansion and contraction of the tank will occur. The effect ofthis is shown by the dashed lines 69 which indicate a torsional movementof the annular footer 67 and a flexing of the fioor 66 as alsoindicatedvin dashed lines. The action illustrated and aboveexplainedrequires torsional and linear freedom to alleviate the highstresses in the side wall which would occur if the base were held rigid.It will be appreciated that the limitation of torsional resistance injthe annular footer coupled with the fiexibility of the floor permits therequired freedom ofmovement. This construction will eliminate the needfor the sliding side wall as portrayed in FIGURES 1 through 6. The tankof the form shown in FIGURE 7, after being Vcast in place, would then beequipped with the insulation material-vapor barrier, and with either ofthe previously described forms for holding the insulation material-linerin place.

While the tank has been illustrated and discussed with regard toliquefied natural gas, it is apparent that the tank would be equallyuseful for storing any other liquid where either eXtreme temperatureconditions or factors of 'safety are material. While the tank has beenillustrated as being underground, it will Vbe appreciated that the tankmight be positioned partially underground,ror it might be at or aboveground level. Underground storage is preferred, as the earth itself willassist in insulating the liquid, and, in the event of a leak, thereresults only little fire hazard. i

The use of the internal insulation and liner supported in the `mannertaught herein'eliminates the necessity for a double-wall constructionwhich has been practiced in the past in above-ground storage. Thereresults a tank which is less costly per gallon of liquid stored,requires less maintenance, and enjoys a' much higher Safety factor thanthe above-ground tanks which have previously been used for storingliquefied gases. i

The term *'cryogenic as used herein includes temperatures between zerodegrees centigrade and absolute zero and is specifically intended Vtoinclude tanks in which substances which are normally gases attemperatures above C. are liquefied and stored at any` temperature lessthan 0 C. Other liquids which may advantageouslybe stored in the tanksofthis invention include liquefied propane or butane.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and various changes in the size,Shape and materials, as well as in the details of the illustratedconstruction, may be made within the scope of the appended claimswithout departing from the spirit of the invention.

What we claim is: g

1. A cryogenic storage tank comprising,

lan outer supportingV shell having a substantia'lly vertical side walland floor and top providing a complete continuous enclosure, said sidewall and floor being made of concrete,

insulation means completely lining said tank including -a plurality ofblocks of insulation material,

a sheet of'continuous impervious :material completely lining the floorand vside wall of said tank. and providing a Liquid and Vvapor barrier,

said insulation means lining said side Wall Varranged in a plurality oflayers with one layer on each side of the portion of the Sheet ofimpervious material lining said side wall,

and means supported on said floor' engaging the inner layerV of saidinsulation means lining said side Wall and holding the insulation meansand sheet of impervious material lining said side wallrin place.

2. A cryogenic storage tank comprising,

an'outer supporting shell having a substantially Vertical side wall,floor and top providing'a complete continuous enclosure, said fioor andside wall being of concrete, i i J insulation means completely liningsaid tank including a plurality of .blocks of insulation material, saidinsulation material lining said'side wall arranged in at i vleasttwolayers,

a sheet of continuous impervious material completely lining saidiloorand side wall of said tank and providing a liner, said imperviousmaterial positioned between said layers of insulation material liningthe side wall and fioor of said tank,

and means including means supported on said floor engaging the innermostlayer of insulation material lining said side wall and floor and holdingsaid insulation material and vapor barrier in place.

3. The underground cryogenic storage tank of claim Z wherein purgegrooves are provided in one of the internal surfaces of said side walland floor of said supporting shell of concrete and the confrontingsurface of said insulation means to provide pathways for purge gas to becarried about the concrete shell and purge therefrom any gas evoivedfrom the fiuid stored in the tank which may be present in the purgepathways.

4. A cryogenic storage tank comprising,

an outer supporting shell having a substantially Vertical side wall,floor and top providing a complete continuous enclosure, said side walland floor being of concrete,

insulation means completely lining said tank including va plurality ofblocks of insulation material arranged in at least two layers with theedges of the blocks staggered and shiplapped to minimize the tendencyfor fluids to flow through the'juncture between two blocks,

a sheet of continuous impervious material completely lining the floorand side wall of said tank and positioned between said layers ofinsulation material which line said side wall and said floor,

i and means supported on said floor holding said insulation material andsheet of impervious material in place including means engaging theinnermost layer of insulation material lining said `side wall and floor.

5. A cryogenic storage tank comprising', i

an outer supporting shell having a substantially vertical side wall,fioor and top providing a complete continuous enclosure, said side walland floor being of concrete,

insulation means completely lining said tank including a plurality ofblocks of insulation material arranged in at least two layers with theedges of the blocks staggered and shiplapped to minimize the tendencyfor fluids to ilow through the juncture between two blocks,

a Sheet of continuousimpervious material completely lining the vsidewall and floor of said tank and positioned 'between said layers ofinsulation material which line said side 'wa'll and said floor,

and means holding said insulation material and sheet of imperviousmaterial in place including,

a plurality of shoes engaging the innermost layer of insulation on theside wall of said tank,

means supported on said floor holding said shoes in spaced relationshipabout the side wall of the tank,

and means urging said shoes radially outward to hold said insulationmaterial and sheet of impervious material in place` 6. A cryogenicstorage tank comprising,

an outer supporting shell having a side wall and floor and top providinga complete continuous enclosure, said side wall and floor being ofconcrete,

insulation means completely lining said tank including a plurality ofblocks of cellular plastic insulation material arranged in at least twolayers with the edges of the blocks staggered and shiplapped to minimizethe tendency for fiuid to flow through the juncture between two blocks,

a sheet of continuous impervious material lining said tank and providinga vapor barrier, said sheet of material positioned between said layersof insulation lining said side wall and floor,

a slab of concrete poured on the insulation material on the floor ofsaid tank,

`and means suspending the top insulation and sheet of material sectionfrom the roof of the tank.

7. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation and liner means completely lining said tank including aplurality of blocks of insulation material and a continuous sheet ofimpervious liner material arranged in layers,

a plurality of vertically extending structural members spaced along theinside of said side wall and having their lower extremities anchoredagainst movement away from said side wall,

means securing the upper extremity of each structural member to saidroof,

a plurality of shoes engaging said insulation and liner means liningsaid side wall,

and resilient means between said shoes and said structural membersurging said shoes and structural members apart and counterbalancing someof the stresses present in said arched roof.

8. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation means completely lining said tank including a plurality ofblocks of cellular plastic insulation material arranged in at least twolayers with the edges of the blocks staggered and shiplapped to minimizethe tendency for fluid to flow through the juncture between two blocks,

a sheet of continuous impervious material arranged in layers with saidinsulation material and providing a liner, said liner sandwiched betweenthe layers of insulation material lining said side wall,

a plurality of Vertically extending structural members spaced along theinside of said tank wall and having their lower extremities anchoredagainst movement away from said wall,

means securing the upper extremities of each structural member to saidroof,

a plurality of shoes engaging the innermost layer of insulation liningthe side wall of said tank,

and resilient means between said shoes and said structural membersurging said structural members and shoes apart and counterbalancing someof the stresses present in said arched roof.

9. A cryogenic storage tank comprising,

an outer supporting shell having a substantially Vertical side wall andfioor and top providing a complete continuous enclosure,

insulation means completely lining said tank,

a sheet of continuous impervious material completely lining the sidewall and fioor of said tank and providin g a liquid and vapor barrier,

a layer of non-rigid protective material lining said side wall inwardlyof and holding said sheet of continuous impervious material against saidside wall,

and means supported on said floor engaging the protective materiallining said side wall and holding the insulation means and sheet ofcontinuous impervious and protective material lining said side wall inplace.

10. A cryogenic storage tank comprising,

an outer supporting shell having a substantially Vertical side wall andfloor and top providing a complete continuous enclosure,

insulation means completely lining said tank,

a sheet of continuous impervious material completely lining the sidewall and floor of said tank and providing a liquid and vapor barrier,

a layer of non-rigid protective material lining said side wall and fioorinwardly of and holding said sheet of continuous impervious materialagainst said fioor and side Wall,

i and means supported on said fioor engaging the protective materiallining said side wall and holding the insulation means and sheet ofcontinuous irnpervious and protective material lining said side wall inplace.

11. A cryogenic storage tank comprising,

an outer supporting shell having a side wall and fioor and top providinga complete continuous enclosure, said side wall and floor being ofconcrete,

insulation means completely lining said tank including a plurality ofblocks of cellular plastic insulation material arranged in at least twolayers with the edges of the blocks staggered and shiplapped to minimizethe tendency for fluid to flow through the juncture between two blocks,

a sheet of continuous impervious material lining the floor and side wallof said tank and providing a vapor barrier, said sheet of materialpositioned between said layers of insulation lining said side wall andfioor,

a slab of concrete poured on the insulation material on the floor ofsaid tank,

a plurality of shoes engaging the innermost layers of insulation on theside walls of said tank,

means supporting said shoes in spaced relationship about the side wallof the tank,

means urging said shoes radially outwardly to hold said insulationmaterial and sheet of material in place in said tank,

and means suspending the top insulation section from` the roof of thetank.

12. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation and liner means lining said tank including a plurality ofblocks of insulation material completely lining said tank and acontinuous sheet ofimpervious liner extending over the floor and sidewall, said blocks of insulation material and impervious liner arrangedin layers over said fioor and side wall,

a plurality of vertically extending structural members spaced along theinside of said side wall and having their lower extremities anchoredagainst movement away from said side wall,

means securing the upper extremity of each structural member to saidroof,

a plurality of shoes engaging said insulation and liner means liningsaid side wall,,

and resilient means between said shoes and said structural membersurging said shoes and structural members apart and counterbalancing someof the stresses present in said arched roof.

13. A cryogenic storage tank comprising,

a concrete base and fioor,

a continuous side wall of concrete resting on said base,

a roof resting on said side wall,

insulation means completely lining said tank including a plurality ofblocks of cellular plastic insulation material arranged in at least twolayers with the edges of the blocks staggered and shiplapped to minimize-the tendency for fluid lto flow through the juncture -between twoblocks,

a sheet of continuous impervious material arranged in layers with saidinsulation material and providing a liner, said liner extending oversaid fioor and side walls and sandwiched between the layers ofinsulation material lining said side wall,

a plurality of vertically extending structural members spaced along theinside of saidtank wall and having References Cited by the ExaminerUNITED STATES PATENTS Kerr 62-54 Jackson 62-54 Klingberg 62-45 Cooper62-45 Kornernann 62-54 Cooper 62-54 Dosl-:er 62-45 Wiedemann et al 62-45Van Bergen et al. 220-9 Dosker 220-9 ROBERT A. OLEARY, Prmaly Examiner.

1. A CRYOGENIC STORAGE TANK COMPRISING, AN OUTER SUPPORTING SHELL HAVINGA SUBSTANTIALLY VERTICAL SIDE WALL AND FLOOR AND TOP PROVIDING ACOMPLATE CONTINUOUS ENCLOSURE, SAID SIDE WALL AND FLOOR BEING MADE OFCONCRETE, INSULATION MEANS COMPLETELY LINING SAID TANK INCLUDING APLURALITY OF BLOCKS OF INSULATION MATERIAL, A SHEET OF CONTINUOUSIMPERVIOUS MATERIAL COMPLETELY LINING THE FLOOR AND SIDE WALL OF SAIDTANK AND PROVIDING A LIQUID AND VAPOR BARRIER, SAID INSULATION MEANSLINING SAID SIDE WALL ARRANGED IN A PLURALITY OF LAYERS WITH ONE LAYERON EACH SIDE OF THE PORTION OF THE SHEET OF IMPERVIOUS MATERIAL LININGSAID SIDE WALL, AND MEANS SUPPORTED ON SAID FLOOR ENGAGING THE INNERLAYER OF SAID INSULATION MEANS LINING SAID SIDE WALL AND HOLDING THEINSULATION MEANS AND SHEET OF IMPERVIOUS MATERIAL LINING SAID SIDE WALLIN PLACE.